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The NCEP Climate Prediction Center, University of East Anglia, and the NCAR Climate and Global Dynamics Division all provide a Darwin SLP time series which begins in the 1800s and is updated monthly. A file of the difference, UEA minus NCEP is linked here. For all but a few months the differences are less than one or two tenths mb. In the following I use the UEA data.
The following SLP anomalies (in tenths mb, for example, 10 is 1.0mb) are with respect to 1950-79.
Monthly SLP anomalies exhibit significant month to month variability,
but I have not filtered the following values.
Data (UEA only)
The numbers are all the same, but are provided in different formats for
different software.
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1866 10 -1 9 4 -1 8 2 4 -1 1 0 6
1867 12 0 13 4 -1 1 -1 -2 -6 -9 18 7
1868 -2 5 10 9 16 14 5 9 6 8 18 5
1869 15 10 23 -25 -15 -13 -4 -13 -4 -14 -9 -11
1870 -23 -12 15 7 10 10 -2 -10 -2 5 7 17
1871 7 7 21 3 4 1 1 1 -3 -4 -5 0
1872 -30 -14 -18 24 -7 -23 -20 -11 -20 -15 -15 -26
1873 -25 9 11 8 23 44 24 10 31 5 2 -22
1874 -3 18 20 1 -6 11 3 3 -11 -19 0 -23
1875 -2 0 22 1 -2 -13 -1 3 -14 -29 3 -4
1876 -14 -11 -10 -11 1 -2 14 2 -3 5 -1 16
1877 6 13 0 16 3 26 19 13 19 21 16 15
1878 6 29 9 4 -2 1 -12 5 -17 -13 -5 -21
1879 -11 -11 -4 0 -2 -4 -12 -10 -8 -6 -10 -4
1880 -19 4 -7 7 -5 1 12 4 6 11 11 10
1881 7 9 18 20 1 2 14 15 12 22 -9 -7
1882 2 0 0 -8 -13 -1 3 6 -1 -11 8 -15
1883 12 2 17 -8 -3 2 0 -8 -1 -4 -16 -4
1884 12 10 0 19 4 2 3 -1 3 3 4 2
1885 12 0 11 12 21 12 13 6 13 20 25 -1
1886 16 -7 11 -2 -3 -1 -11 -14 -11 -7 -6 -28
1887 -5 -17 -3 -8 0 2 6 -1 3 7 8 9
1888 -8 7 24 12 4 9 10 9 6 17 11 16
1889 29 21 27 8 4 -11 0 3 -11 -4 -30 -28
1890 -22 0 -6 -5 0 -8 -4 -4 -14 -7 4 2
1891 -8 4 17 8 14 9 13 23 20 10 14 16
1892 2 17 -13 5 10 -5 3 -4 -7 -14 -6 -1
1893 -5 -7 14 -2 4 -5 -7 6 -4 -10 1 6
1894 -28 -3 0 2 10 6 10 -1 3 3 4 6
1895 -8 7 11 8 14 6 0 -1 -1 3 21 6
1896 -1 -3 4 -2 31 9 6 23 16 24 14 23
1897 16 10 24 15 17 2 10 6 -1 3 4 -15
1898 -1 -13 -34 -2 7 -1 3 -1 -11 -10 -19 -11
1899 -8 7 -13 -2 7 9 6 3 6 14 11 9
1900 16 17 24 15 7 -4 -7 -14 -4 0 4 13
1901 2 4 1 5 7 -1 3 6 10 0 11 3
1902 -4 17 7 9 21 9 10 9 16 17 21 13
1903 19 21 -16 -2 4 6 -14 3 -7 -3 -2 -18
1904 -4 -10 -3 -18 0 9 3 6 3 -7 15 6
1905 16 14 34 15 4 6 10 9 0 -3 21 13
1906 2 7 11 5 4 -1 -10 -1 -14 -7 -16 -4
1907 -11 -3 7 5 7 -8 -4 3 3 0 1 -14
1908 16 -10 -3 -12 4 6 0 -1 0 -3 -2 -1
1909 -4 14 -16 5 -3 -8 -7 -7 -7 -10 -6 -4
1910 -18 -13 -6 -12 4 -11 -10 -7 -14 0 -16 -14
1911 -8 -6 4 -8 11 16 6 9 3 14 11 3
1912 13 27 7 22 17 2 -10 6 -7 7 1 13
1913 -1 7 -6 2 17 9 10 3 13 14 15 9
1914 23 21 1 12 4 12 13 23 16 30 21 13
1915 23 14 31 19 11 -4 -10 -1 -14 -7 -2 -18
1916 -11 -3 1 5 -10 -18 -17 -4 -11 -14 -9 -31
1917 -1 11 -16 -8 -3 -11 -21 -18 -14 -7 -12 -21
1918 -8 -10 14 -2 0 2 10 9 23 7 4 9
1919 9 24 11 2 0 6 3 9 6 7 11 9
1920 -11 4 14 -5 0 -21 -17 -7 -7 -3 -2 -18
1921 -11 0 -6 9 -6 -18 -7 6 0 0 1 -11
1922 -8 -13 -6 2 -3 -8 -4 3 -4 0 1 -11
1923 -11 0 -10 -12 -6 -8 10 20 6 10 8 -1
1924 13 4 1 2 -3 -1 3 3 0 -10 -6 -14
1925 -8 -23 -23 -15 -3 -1 10 3 10 10 15 9
1926 2 21 21 9 4 6 0 3 -4 -7 8 -8
1927 -11 4 -6 -5 0 -4 -4 6 6 7 8 -1
1928 23 -6 -10 -2 11 6 0 6 0 -10 8 -8
1929 -32 -20 1 2 11 12 10 6 6 3 -6 -8
1930 -15 0 7 9 11 6 6 9 13 14 21 6
1931 2 21 11 2 7 2 3 -1 -7 10 1 -4
1932 -8 11 4 9 4 2 6 9 -4 -3 4 -8
1933 6 -10 -6 2 4 2 0 6 0 -7 -6 -8
1934 -4 11 -3 -5 7 -4 -4 9 3 3 -2 3
1935 -8 11 -13 2 14 6 0 9 -11 -7 4 9
1936 6 4 1 -2 -6 2 -4 -4 -4 3 8 -4
1937 -11 14 -13 -2 11 -1 6 -1 6 3 -6 -8
1938 -11 -6 7 -2 -10 -8 -10 -11 0 3 -9 -4
1939 -15 -6 -10 -2 4 2 0 -11 13 10 4 19
1940 -4 0 14 15 14 16 13 16 23 34 8 26
1941 16 33 13 13 4 14 25 19 8 14 5 16
1942 23 -1 12 10 -10 -5 3 -5 -8 -10 -4 -5
1943 1 -15 0 -5 0 8 -3 -6 -8 -8 -3 5
1944 10 3 2 9 8 8 11 9 5 8 3 -9
1945 3 0 -16 10 5 -5 5 -4 0 6 6 0
1946 1 -9 12 11 8 9 9 8 8 13 5 1
1947 13 -1 -4 3 16 3 3 -10 -4 1 -5 -5
1948 11 1 2 -3 0 4 -6 -4 3 -1 -11 5
1949 11 -8 -12 8 3 12 1 8 -1 -7 3 -20
1950 -15 -21 -9 -16 -9 -16 -8 -6 -2 -10 -22 -28
1951 -9 -13 -4 1 11 -11 4 6 6 9 8 17
1952 5 7 9 10 -5 2 1 0 2 -6 -10 12
1953 7 9 6 -4 23 2 10 4 13 3 7 9
1954 -13 9 3 -16 -7 0 -5 -8 0 2 4 -7
1955 21 -27 -7 -4 -14 -14 -12 -12 -10 -12 -11 4
1956 -14 -17 -5 -10 -17 -10 -17 -11 -5 -8 0 -16
1957 3 0 4 2 15 2 0 7 12 10 11 5
1958 23 7 7 -4 1 -7 -5 -10 -4 -9 4 11
1959 -1 23 -5 -4 -4 5 6 5 0 0 -10 -11
1960 3 3 -3 -8 -8 2 -4 -1 -14 2 0 0
1961 11 0 21 -1 4 6 2 5 2 -1 6 -3
1962 -11 10 10 4 -6 -6 -6 9 -7 -7 -4 2
1963 -2 16 -7 -6 -4 11 7 -2 9 18 18 19
1964 11 7 -3 -1 -3 -3 -8 -4 -14 -10 -8 5
1965 2 -6 -5 21 3 18 27 11 15 20 17 -5
1966 13 5 13 7 15 10 1 1 2 8 3 5
1967 -11 -7 -1 14 3 2 -1 2 10 4 2 7
1968 -21 -13 9 5 -12 0 -2 2 4 6 12 2
1969 -4 1 10 17 3 4 7 9 0 10 5 -2
1970 21 8 -2 8 -1 -4 10 -6 -17 -17 -13 -18
1971 -4 -19 -14 -13 -4 7 -4 -9 -11 -10 -4 -14
1972 -4 -13 -7 13 16 5 9 12 18 21 11 24
1973 11 19 0 -3 0 -13 -5 -11 -5 -9 -29 -6
1974 -22 -20 -19 -5 2 1 -2 -5 -9 -8 -9 -7
1975 3 5 -8 -15 -4 -9 -11 -13 -14 -16 -5 -16
1976 -11 -10 -18 6 12 2 13 15 11 -5 -10 -7
1977 -4 -8 7 -1 5 12 7 10 11 18 13 9
1978 20 25 21 8 -15 -12 -16 -7 -3 2 8 2
1979 -2 5 5 4 4 3 17 7 -2 5 4 13
1980 -3 -1 -2 4 5 2 3 8 8 2 4 1
1981 -11 -2 25 6 -3 -8 -11 -2 -4 6 -3 3
1982 3 6 1 8 11 16 16 21 24 20 24 21
1983 36 39 27 8 9 10 15 15 2 0 10 13
1984 9 -11 7 8 3 9 3 -4 -2 8 6 -21
1985 15 -10 -13 -18 -14 3 7 -2 -4 2 -3 4
1986 -15 5 10 0 8 -13 -1 -6 3 4 6 25
1987 9 10 33 22 18 8 19 17 16 7 2 6
1988 16 3 -6 8 0 16 -1 -1 -13 -14 -13 -6
1989 -8 4 -1 -17 -7 5 -8 7 -2 -6 0 16
1990 7 36 9 4 -5 1 -1 9 14 9 4 5
1991 1 1 21 6 18 10 5 14 14 6 14 13
1992 39 13 31 17 3 2 18 2 -7 7 8 1
1993 6 0 27 21 16 16 6 25 15 15 3 -2
1994 5 1 20 15 12 6 12 23 16 14 11 21
1995 8 14 -2 3 8 7 -2 6 1 -3 1 3
1996 -5 -2 0 -2 14 1 -4 0 -16 -6 -3 -16
1997 11 -16 12 26 11 24 14 25 28 27 27 14
1998 16 38 26 17 7 -1 -4 2 -2 -8 -13 -13
1999 -13 -2 -10 -6 13 7 3 13 5 -2 -7 -6
2000 5 1 0 -7 9 12 2 -4 1 -13 -22 -24
2001 10 -999 -999 -999 -999 -999 -999 -999 -999 -999 -999 -999
March 2001
Todd Mitchell (mitchell@atmos.washington.edu)